A Black hole is one of the mysterious things of the universe. They are so massive and heavy and have so much gravitational pull that even light cannot escape. Black hole appears when an extraordinary amount of matter concentrates in a tiny space. If you
want to create a black hole which weights equivalent to the weight of the earth then you will have to crush the earth to the size of a marble. Now you can imagine the weight of a black hole if it would be as big as our sun. In
universe there exists infinite number of black hole. The largest black hole ever discovered is S50014+81, that’s a strange name, it weights 40 billion times the mass of sun and its diameter is 47 times the distance from sun to
At the centre of the black hole the gravity is infinitely strong and at centre the point in which all the mass has been concentrated is known as singularity, it’s a one dimensional point where the laws of physics as we know them come to an end to operate. An event horizon is like a border of a black hole, if an object crosses this border then there is no way to return back, the object will gain mass million times as it moves toward the singularity. Nothing can escape black hole once it gets too close. We still don’t know what really going on inside a black hole.
Now what will happen if we replace the sun with a black hole, you may think that within few minutes the mercury will get destroy, it will get big and eventually earth would be swallowed by the black hole. But nothing will happen like that, in fact all the planets will orbit the black hole as they were orbiting the sun, and earth will freeze and life would come to an end.
Another question arises that what will happen if there is nothing to feed the black hole , black hole will eventually loss its mass over a period of time and that process is incredibly slow , a black hole will take 10 billion billion billion years to lose just 0.0000001 % mass of sun. A black hole also radiates some energy radiation from its event horizon known as hawking radiation.